机械刺激诱发的吞咽样行为由一条咽至脑的感觉通路介导。

文献信息

中文摘要

作为与喉共享解剖入口的结构，吞咽不仅在食物和水的摄入中发挥重要作用，也在防止异物误吸风险的防御机制中起主要作用。除水/酸之外，食物或异物的机械刺激也可诱发吞咽，但相关的感觉通路仍知之甚少。在此，我们以雄性小鼠为模型，阐明表达Piezo2的迷走感觉神经元负责将吞咽诱发的机械刺激从咽部传递至孤束核（NTS）中的酪氨酸羟化酶阳性（TH+）神经元，再传递至疑核/延髓头端腹外侧区（Amb/RVLM复合体）。特异性激活Piezo2+迷走感觉神经元或TH+ NTS神经元可诱发吞咽行为。而抑制TH+ NTS神经元或在迷走感觉神经元中敲除Piezo2均可消除吞咽反射。值得注意的是，我们阐明TH+ NTS-Amb/RVLM通路是机械刺激和化学刺激诱发吞咽所共享的下游通路。总之，我们描述了一条咽至脑的感觉通路，为吞咽与气道防御反射的中枢整合提供了基础。

英文摘要

As sharing the anatomical entrance to the larynx, swallowing plays not only an important role in food and water intake, but also a major role in defensive mechanism for preventing the risk of foreign matter aspiration. Besides water/acid, the mechanical stimulation of food or foreign matter could induce swallowing, yet the relevant sensory pathways remain poorly understood. Here, using male mice as a model, we clarify that vagal sensory neurons expressing Piezo2 responsibly transmit swallowing induced mechanical stimuli from the pharynx to tyrosine hydroxylase positive (TH + ) neurons in the nucleus of the solitary tract (NTS), then to ambiguus nucleus/rostral ventrolateral medulla (Amb/RVLM complex). Specific activation of Piezo2+ vagal sensory neurons or TH + NTS neurons can induce swallowing behavior. Either inhibition of TH + NTS neurons or Piezo2 knockout in vagal sensory neurons can abolish swallowing reflex. Notably, we elucidate that the TH + NTS-Amb/RVLM pathway serves as a shared downstream pathway for both mechanical and chemical stimuli-elicited swallowing. Collectively, we describe a pharynx-to-brain sensory pathway that provides a basis for central integration of swallowing and airway defensive reflexes.